Field:
In one aspect, the following relates to processor microarchitecture and memory subsystems, and in one particular aspect, to approaches to processing memory transactions.
Related Art:
Processors require data on which to operate. Many processor architectures support a set of registers (a register file) that store data that can be used as operands for instructions. Access to a register file is fast. However, an amount of data that can be stored in a register file is relatively small (on the order of 32 64 bit words). Main memory is orders of magnitude cheaper and more plentiful than a register file. However, accessing main memory also is orders of magnitude slower than accessing a register file. Cache memories are interposed between a register file and a main memory in order to reduce traffic to and from main memory. Caches are often managed by hardware (rather than controlled by software), although some processor architectures support capabilities to pre-fetch data into a cache, for example. Caches generally operate on a principal of temporal locality of reference to data, which means that data that was recently used is more likely to be used again.